In contemporary society, vibration and noise in the road nearby buildings have become social problems as vehicles operation has increased. Especially, in the case of the building used to art performance, available suitability of the building is tested by the indoor noise class. Therefore, the purpose of this paper is the measurement of the structure-borne noise of Seoul Art Center nearby Umyeonsan tunnel and analyzing the effects of countermeasure to it. To measure the effects of countermeasure, not only structure-borne noise is measured, but also the vibration is measured, before and after the construction of pavement using pad and porous asphalt. Consequently, the sound pressure level in art center 1st floor is reduced after mat pavement method, structure-borne noise that was high in 25Hz wide-band before pavement decreased regardless of experimental vehicle's velocity. Using porous asphalt pavement the noise was reduced about 3 dB(A).

The object of research in Based on 1.5MW wind turbine blade. This paper has carried out the aerodynamic shape optimization design of wind turbine blade. Based on the aerodynamic basic theory of wind turbine blade design and combined with particle swarm optimization algorithm, the design optimization model of the aerodynamic shape of blade is established. The calculation programs are written by use of MATLAB and calculate chord length and torsion angle of the blade. Then the shape of wind turbine blade is obtained. As research we can know that the chord length is decreased after optimization design of wind turbine blade, The optimized blade not only meets the actual manufacturing requirement, but also has the largest wind energy utilization coefficient.

Semiconductor is one of the biggest export items in Korea and one of future foods. In this study, the development of the product due to the repetition of the engineer mistakes repeatedly occurred due to the experience and habit of the individual in the semiconductor design process until now, resulting in an increase in the development period of the product and the economic loss of sales. As a result, the need for database of engineers' knowledge and know-how has emerged. This study investigate show to integrate and utilize data that is not managed on On/off-line for semiconductor knowledge and know-how. To do this, we intend to construct a RCT(RootCauseTracker) system that enables statistical analysis of the data on design failure accumulated over the previous year in any company.

PURPOSES :This study proposes standards for rural access road pavement section and thickness design considering existing access road construction conditions; the study also proposes a complementary policy that can be used for design convenience.METHODS:Various literature review and case studies had been performed in terms of rural access road section and thickness design, both domestically and internationally, and this was followed by domestic rural access road field surveys. KPRP and KENLAYER were used to analyze the commonalities and predict the remaining life. Data on real cost is used to select an appropriate construction method through economic analysis.RESULTS:The economic efficiency of concrete pavement (15×15) was the highest in terms of economic efficiency of performance life and traffic volume. In the case of asphalt pavement, it is considered that the most economical method is to implement micro-surfacing method four times as a preventive maintenance method (once every 10 years and 4.5 years for asphalt concrete pavement and MS construction method, respectively). Repairable asphalt pavement is advantageous for areas where heavy vehicles are expected to pass. In the case of other general areas, it is considered economical to place concrete (15×15) pavement. However, as analytical results on its performance life are unavailable, it is to be considered for study in the future.CONCLUSIONS :This study proposed interim design guidelines based on various domestic and international design guidelines and case studies. However, in order to develop the final design criteria applicable to the field, it is necessary to (a) estimate the bearing capacity of the lower level of the pavement at various sites, (b) estimate the daily traffic volume, (c) implement advanced low-cost pavement technologies, and (d) propose maintenance standards and techniques for long-term performance.

A most important progress in civilization was the introduction of mass production. One of main methods for mass production is die-casting molds. Due to the high velocity of the liquid metal, aluminum die-casting is so complex where flow momentum is critical matter in the mold filling process. Actually in complex parts, it is almost impossible to calculate the exact mold filling performance with using experimental knowledge. To manufacture the lightweight automobile bodies, aluminum die-castings play a definitive role in the automotive part industry. Due to this condition in the design procedure, the simulation is becoming more important. Simulation can make a casting system optimal and also elevate the casting quality with less experiment. The most advantage of using simulation programs is the time and cost saving of the casting layout design. For a die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize the casting layout design of an automotive Oil Pan_BR2E, Computer Aided Engineering (CAE) simulation was performed with three layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process with three models, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflows. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system.

As a preparation of a design standard regarding road facilities in terms of reliability based optimum design examples, such as cantilever columns for traffic lights, optimum design in deterministic and probabilistic ways for the foundation of traffic lights poles are proposed. Most of the previous study have focused on the foundation surrounded by cohesionless soil. However, the design would be governed by risky condition. Therefore the resistance by clay-soil is investigated compared with other design specifications. In deterministic optimization, GRG method is applied. It is found that both geometries of deep and shallow foundation provides optimum values. The resistance of cohesive soil is selected to represent the ultimate limit states, in terms of sliding, overturning and bearing pressures from super structures to the foundation under external loads. Example foundations with varying height of columns for traffic lights are optimized about 30% decreased embedded depth of foundation. The optimum coefficients of resistant and load factors may need to be developed with design load combinations in order to prepare design specifications as the next step.

지난 수십 년간 공공시설 및 사유지 적용을 위한 롤러전압콘크리트포장의 사용실적은 꾸준히 증가 하고 있는 추세이다. 롤러전압콘크리트포장은 아스팔트포장의 시공특성과 전통적 콘크리트포장의 재 료적 특성을 동시에 나타낸다. 또한 작업성(workability)과 다짐성(compactibility)은 롤러전압콘크 리트포장의 우수한 배합설계를 결정하기 위한 주요요소로써, 강도가 충분히 확보된 콘크리트라 할지 라도 적정 반죽질기 또는 작업성이 확보되지 않으면 시공이 용이하지 않을 수 있다. 일반적으로 포장 적용을 위한 롤러전압콘크리트의 배합설계 시 흙다짐 방법 및 반죽질기 방법을 사 용하고 있으나, 흙다짐 방법의 경우 작업성을 고려하지 못하며 반죽질기 방법은 작업성만을 고려하고 있다. 이에 본 연구에서는 포장 적용을 위한 롤러전압콘크리트에 대하여 실내실험 변수와 현장 공용성을 모두 만족시키는 배합설계방법의 개선방안을 제안하였다. 이를 위하여 실내실험 변수를 현장 공용성 으로 연계하여 적정 공용성을 확보할 수 있는 최적 롤러전압콘크리트 배합을 도출하였으며, 롤러전압 콘크리트의 주요 물성인 반죽질기, 강도 및 내구성과 배합비 간의 상관관계를 규명하기 위하여 다양 한 실내실험을 진행하였다. 또한 실제 현장 조건에서 이와 같은 물성들을 연계시키기 위하여 속초인 근 고속도로 부체도로에 총 5개 구간의 롤러전압콘크리트포장을 시공하여 품질관리 변수인 반죽질기 에 근거하는 하중지지력과 표면 물성에 대하여 조사하였다. 이와 같은 물성들의 새로운 이해는 포장 적용을 위한 롤러전압콘크리트의 배합설계절차 개선으로 이어진다.

In this study, we changed the existing S45C steel shafts applied to the drive shaft for power train of automotive to Al7003-T6 aluminum material. For this purpose, the optimal inner diameter of the aluminium shaft is established. And, analysis of the stresses and vibration characteristics of shafts were analyzed through finite element analysis. The final aluminum drive shaft was evaluated through the static torsional torque test and the frequency test. The Al7003-T6 aluminum drive shaft's weight is 67% comparing from 100% of shaft with existing steel, and with the performance of 3,276 N-m and 236 Hz, it satisfies requirements of the torsional torque of 3,000 N-m and vibration characteristic over 150 Hz required for drive shaft.

RTG (Radioisotope Thermoelectric Generator) is a power generation system producing electricity by converting the thermal energy gained from shielding radioisotope. RTG generates power without being charged from outside and as it utilizes radioisotope, RTG mainly serves as an energy source operated for a specific purpose in environment hardly accessible by human. Its design structures vary according to its purpose of operation, thermal source of operation and environment of operation. Since RTG is a power generation system, it should have the highest power efficiency with limited heat source. In this study, heat transfer analysis was implemented to investigate diverse design factors influencing the insulation system of RTG for aerospace use. Design factors considered in this study were silver coating, number of radiation shields inside vacuum insulation and supporter material. As a result, it was found that, depending upon design factors, insulation efficiency increased by 9.3% and finally insulation efficiency of RTG v2.0 was estimated at 84.3%.

PURPOSES : The purpose of this study is to investigate the fundamental behaviors such as stresses and deflections of the middle slab in a double-deck tunnel for the development of a middle slab design guide. METHODS : The middle slab has been divided into the following three different sections as according to its structural differences: the normal section, expansion joint section, and emergency passageway section. The normal section of middle slab represents the slab supported by brackets installed continuously along the longitudinal direction of tunnel lining. The expansion joint section refers to a discontinuity of middle slab due to the existence of a transverse expansion joint. The emergency passageway section has an empty rectangular space in the middle slab that acts as an exit in an emergency. The finite element analysis models of these three sections of middle slab have been developed to analyze their respective behaviors. RESULTS: The stresses and deflections of middle slab at the three different sections decrease as the slab thickness increases. The emergency passageway section yields the largest stresses and deflections, with the normal section yielding the smallest. CONCLUSIONS: The stress concentrations at the corners of the passageway rectangular space can be reduced by creating hunch areas at the corners. The stresses and deflections in the emergency passageway section can be significantly decreased by attaching beams under the middle slab in the passageway area.

In this paper, a structural integrity on the test rig with assembly plug to perform intermediate examination is evaluated. Structural analysis results between the test rig with non assembly plug and assembly plug are compared, because the assembly plug has an effect on the flow of the coolant in the test rig. A equivalent stress value on the test rig with assembly plug is increased more than the stress on the test rig with non-assembly plug. A shape optimization of the assembly plug is performed to decrease the stress. Considering a connection with the transport tool, a optimized shape of the assembly plug is presented to minimize the stress on the test rig. Using the optimized assembly plug, the equivalent stress on the test rig with the optimized plug is less than the stress on the test rig with the non-optimized plug.

본 연구에서는 페이즈필드 설계법에 기반한 형상최적설계를 통해 개선된 패치안테나 금속 패치 부분의 형상 설계를 진행 하였다. 설계 목적은 패치 안테나의 목적 주파수에서의 방사 효율을 최대화 하는 것으로 설정하였고, 이에 따라 목적 함수는 반사손실을 나타내는 S-파라미터 값의 최소화로 정의하였다. 패치형상의 최적화 결과는 페이즈필드 설계법을 이용하여 도 출하였고, 최적화 결과의 회색영역을 제거하기 위해서 컷오프 방법을 적용하였다. 더불어 쿼터 정합기의 길이 변화를 통해 성능 개선 과정을 진행하였다. 이를 통해 도출해낸 최종 형상에 대한 해석 결과, 목표 주파수에서의 S-파라미터 값이 -1.14dB에서 -12.73dB로 개선됨을 확인하였다.